Author Topic: Applent AT8612 DC load - a quick tear down  (Read 23591 times)

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Offline thefamilyman

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Applent AT8612 DC load - a quick tear down
« on: July 03, 2015, 07:55:19 am »
Hello everyone

I'm new to the forum so i'll like to contribute a little something.
I purchased myself an electronic DC load for my testing purposes at work, I looked everywhere and looked at the Maynuo and BK units plus some others.
After some extensive self research and including reading on these forums I decided to venture a little into the unknown with the Applent AT8612.
I've noticed that their LCR meters are popular so i wanted to see how their DC load measured up.

My initial criteria was a 300W load, the Maynuo 300W units were a bit pricey so the AT8612 became even more tempting at US$360+shipping.

After a few months using it pretty much everyday I can say I am very happy with it.
Some thoughts:
I'm a sucker for LCD screens, you could sell me a poo if it had an LCD on it. The menu and screen is truly wonderful to use and looks even better than the photos portray.
Binding posts that I can use my standard (non shielded) 4mm banana plugs - a massive win! It still has binding posts too. This is a HUGE plus!
There was a UI bug where under certain conditions it wouldn't read the voltage correctly, but after contacting Applent directly the next day they emailed me a firmware update that fixed the problem.
4 wire sense is very useful and accurate.
Battery capacity test is quite useful.
Extremely quiet, even under full load the fans are very quiet but still move sufficient amounts of air.

It can test much of your standard tests like:
CC, CV, Constant Power, Constant Resistance, Transient CC CV CP CR, Battery testing, Sequence testing, Automatic testing.
150V, 30A, 300W.

As I said, it's only a quick tear down and brief review. I am more than happy to do a more extensive tear down and answer more detailed questions from my first hand experience.
The micro-controller is behind the transformer and I couldn't read it properly so in my more detailed tear down i'll take a closer look.

 
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Online Mr.B

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Re: Applent AT8612 DC load - a quick tear down
« Reply #1 on: July 03, 2015, 08:25:06 am »
Welcome to the forum.
Thanks for your contribution.
It looks like quite a nice unit.
I have a Maynuo and really like it.

Now...
Off to start my new kickstarter... "LCD equipped poo"
I know I will have at least one backer.  ;D
Time is the overseer of all things.
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #2 on: July 03, 2015, 08:27:22 am »
Now...
Off to start my new kickstarter... "LCD equipped poo"
I know I will have at least one backer.  ;D

 

Online mcinque

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Re: Applent AT8612 DC load - a quick tear down
« Reply #3 on: July 03, 2015, 11:24:03 am »
Hi, thank you for sharing the pics!  :-+
I'm basically still a rookie and because of this, even with the best intentions, I often say bullshits
 

Offline PedroDaGr8

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Re: Applent AT8612 DC load - a quick tear down
« Reply #4 on: July 03, 2015, 06:33:28 pm »
VERY interesting, while the interface is different, the load portion itself is very much related to the Mayuno M9812 but with upgraded parts.

Maynuo:


Yours:
https://www.eevblog.com/forum/testgear/applent-at8612-dc-load-a-quick-tear-down/?action=dlattach;attach=159539;image

Yours has upgraded vertical sandstone resistors instead of the flat laying large wattage resistors. Yours has a higher quality R-core transformer. In general, the fit and finish look much better on yours than the Maynuo but there is VERY clearly a strong relationship between the designs. Everything is in the same general locations, most of the same parts are there, etc. It looks like one is a revision of the other and that is it.

EDIT: Your LCD-POO comment made me actually laugh out loud.
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves, "You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." -George Carlin
 

Offline smgvbest

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Re: Applent AT8612 DC load - a quick tear down
« Reply #5 on: July 04, 2015, 06:37:46 am »
I purchased one of these as well and have been very happy with it
Thanks for doing the quick tear down,  I had wanted to do it but it's very heavy and once I got in into place on my bench I've not wanted to move it.   :phew:

@thefamilyman
I'd love to get the firmware update if you have it?
Sandra
(Yes, I am a Woman :p )
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #6 on: July 05, 2015, 02:19:48 pm »
PM me your email and I'll send it to you
 

Offline tridentsx

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Re: Applent AT8612 DC load - a quick tear down
« Reply #7 on: July 30, 2015, 06:43:11 am »

I have seen the same load under a different brand

http://www.ebay.com/itm/Programmable-Electronic-Load-300W-150V-30A-3-5TFTLCD-RS232-Battery-Test-AT8612-/301683686532?pt=LH_DefaultDomain_0&hash=item463dbfbc84

Ayone knows if its the exact same unit same quality ? It is cheaper and seems to use a different binding post.
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #8 on: July 30, 2015, 07:01:17 am »

I have seen the same load under a different brand

http://www.ebay.com/itm/Programmable-Electronic-Load-300W-150V-30A-3-5TFTLCD-RS232-Battery-Test-AT8612-/301683686532?pt=LH_DefaultDomain_0&hash=item463dbfbc84

Ayone knows if its the exact same unit same quality ? It is cheaper and seems to use a different binding post.

its the exact same unit as mine.
Anbai is the chinese name for Applent, the same company.

the ebay link is the same seller as i bought mine from aliexpress, it's cheaper on Ali too.
http://www.aliexpress.com/item/Programmable-DC-Electronic-Load-300W-150V-30A-3-5-TFT-LCD-RS232-Handler-Battery-Test-Max/1970741643.html
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #9 on: November 04, 2015, 03:52:39 pm »
Hi thefamilyman,

I also recently purchased the AT8612, and I'm quite pleased by its performance and build quality.
It's amazing how it can sustain loads in eccess of 850 watts without a hitch.

I also use a lot the BAT function, but there's a problem: when discharging a regular battery, as soon as its voltage drops below the threshold value the load shuts down and I can read the accumulated mAh's.
If I want to test a so called "smart" battery (the kind of which shuts itself off when discharged), the load shuts also off, but the mAh reading resets to 0.

This behavior can be reproduced connecting a power supply to the load: if I progressively lower the supply voltage below the set threshold, the load stops and mAh stay there.
If I instead shut off the power supply, the load stops BUT the mAh readings suddenly go to 0.

I tried to contact applent.com (anbai.cn) some days ago, but with no reply so far.

Maybe there's some chance the FW update they sent you also takes care of this issue (but I know it's too likely); would you mind send me a copy to lfilardi [at] alice [dot ] it?
My current FW is REV A2.7 under V6.0 OS version.

Another thing: is found that the front USB port readily recognizes USB sticks, but I could'n find a way to use it.
Anybody knows anything about it?

Thanks a lot!

    Lucio.
 

Offline tridentsx

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Re: Applent AT8612 DC load - a quick tear down
« Reply #10 on: November 09, 2015, 03:42:46 pm »

Does it have switchable mains ? It looks like transformer has two windings on primary. I can only find 220v model listed on ebay.
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #11 on: November 09, 2015, 06:06:29 pm »
My (220V) unit has a 110/220 V rear switch, but it is not connected!
The diagram printed onto the transformer shows two separate 110 V windings, but they are connected in series without passing through the switch.

Anyway, to be sure, it would be better to choose the right voltage when ordering.
I got my unit from Aliexpress and saved quite a lot - even selecting the "expedite" FedEx shipping.
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #12 on: November 13, 2015, 04:57:34 am »
Hi thefamilyman,

I also recently purchased the AT8612, and I'm quite pleased by its performance and build quality.
It's amazing how it can sustain loads in eccess of 850 watts without a hitch.

I also use a lot the BAT function, but there's a problem: when discharging a regular battery, as soon as its voltage drops below the threshold value the load shuts down and I can read the accumulated mAh's.
If I want to test a so called "smart" battery (the kind of which shuts itself off when discharged), the load shuts also off, but the mAh reading resets to 0.

This behavior can be reproduced connecting a power supply to the load: if I progressively lower the supply voltage below the set threshold, the load stops and mAh stay there.
If I instead shut off the power supply, the load stops BUT the mAh readings suddenly go to 0.

I tried to contact applent.com (anbai.cn) some days ago, but with no reply so far.

Maybe there's some chance the FW update they sent you also takes care of this issue (but I know it's too likely); would you mind send me a copy to lfilardi [at] alice [dot ] it?
My current FW is REV A2.7 under V6.0 OS version.

Another thing: is found that the front USB port readily recognizes USB sticks, but I could'n find a way to use it.
Anybody knows anything about it?

Thanks a lot!

    Lucio.

Hi

my firmware version is A2.2 and thats after a few firmware upgrades from small bugs that i've pointed out to Applent.
i've messaged Applent just now to see whats the difference between my FW and yours.

you can email directly to Applent, they are very helpful and fast to fix bugs (big surprise!) her mail is vera@applent.com

i'll attach my firmware and a pic of my current system info.

 

Offline crispy_tofu

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Re: Applent AT8612 DC load - a quick tear down
« Reply #13 on: November 13, 2015, 06:49:59 am »
Thanks for the teardown!  :-+

Now...
Off to start my new kickstarter... "LCD equipped poo"
I know I will have at least one backer.  ;D

I'd buy the crap out of that.  ^-^
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #14 on: November 13, 2015, 04:05:40 pm »
Thanks thefamilyman,

I sent a request to Applent/anbai through their messaging system, but didn't get a reply so far; I'll try to send an email to vera.

I'll also ask for the System Service password, which should allow me to mess with the calibration...
It's almost OK for now (just out by a couple of digits), but I'd like to be able to recalibrate the meters, just in case...

Regards,
    Lucio.
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #15 on: November 18, 2015, 01:35:47 pm »
Hi,
this unit looks interresting.

Some short questions:

Is der any Software with it?
Has it an USB Interface on board or is a external Interface necessary?
Does anybody know where the Operator's Manual can be downloaded?

Thx

Torsten
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #16 on: November 18, 2015, 02:20:00 pm »
Hi Torsten,

the unit comes without any software and with a printed manual, along with a pair of banana-alligator cables, a RS-232 cable, and a calibration/test sheet.
For what I know, no online manual is available.

On the anbai/applent website a dedicated software can be downloaded, but it's only in Chinese so far.

On the front panel there is an USB connector which explicitly recognizes FAT32 pendrives, but I found no way to use it, except to firmware updates.

Finally, on the rear there is a DB9F RS-232 connector.
It is a 2-wire only (RX, TX) RS232 interface responding to SCPI language (you can set the instrument parameters, send commands and read measured values; a cheap serial-USB interface should work fine).

I've not tried the more sophisticated functions yet, but in NORMAL and BATTERY modes it works wery well.
Although it's a 300W / 120V unit, I could make it work up to 300 V and over 500W for a few minutes without problems.

I also found some minor bugs, but they were promptly solved by firmware updates (usually within as day) emailing the issue to Vera (see previous messages).

Hope this helps.

    Lucio.
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #17 on: November 18, 2015, 02:57:57 pm »
Hi Lucio,

thank You very much for sharing your experiences and for the fast reply.
I suspected something like this, regarding the Software und USB-Interface.
Is this a real RS232 Interface or has it TTL-Level? In this case a Levelshifter is required (as for other elctr. Loads from other Brands).

Kind regards

Torsten
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #18 on: November 18, 2015, 03:05:31 pm »
Is this a real RS232 Interface or has it TTL-Level? In this case a Levelshifter is required (as for other elctr. Loads from other Brands).

It works at RS-232 levels thru a MAX3232 chip.

Regards,
    Lucio.
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #19 on: November 18, 2015, 03:16:45 pm »
just to be shure (and not lost in translation :-)  , the RS232 Transceiver is onboard?

Kind Regards

Torsten

 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #20 on: November 18, 2015, 03:31:26 pm »
just to be shure (and not lost in translation :-)  , the RS232 Transceiver is onboard?

Yes, I did mean that the MAX3232 transceiver is on-board, so the AT8612 serial port can be directly connected to a standard RS-232 port.
Remember that it only uses 3 wires: GND, RX and TX - so there's no hardware handshaking.

    Lucio.
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #21 on: November 18, 2015, 03:48:53 pm »
yes, I know. But is there no levelshifter on board and this Unit will be connected to a real RS232 Interface (+- 15V), the Unit will, or could be, damaged.
BTW..I have no PC with a real RS232 anymore, so I have to Interface from USB to (real) RS232 Level ....in case of I will buy the Applent...

Torsten
« Last Edit: November 18, 2015, 03:52:06 pm by AgiRigSig »
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #22 on: November 18, 2015, 04:33:34 pm »
Well, maybe I didn't understand correctly...
I can confirm that the level shifter is included inside the AT8612 unit, so its serial port is made to be connected to an RS-232 port (not TTL levels).

To be exact, the AT8212 serial output typically swings between -5,4 and +5.4 V
The serial input can withstand up to +/- 25 V.

A serial to USB interface should work fine; in my experience, the best ones among cheap interfaces are those with FTDI (FT232 series) chips.

    Lucio.
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #23 on: November 18, 2015, 04:40:15 pm »
Tank you very much Lucio, now all is clear...
I'm just looking at Anbais Website...

Torsten


 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #24 on: November 18, 2015, 07:30:47 pm »
I've got a copy of the software in English that I will share later on

as promised:
https://dl.dropboxusercontent.com/u/1044245/EEVBlog/DCLoad/AT861x_ENsetup.zip
« Last Edit: November 18, 2015, 08:41:01 pm by thefamilyman »
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #25 on: November 19, 2015, 04:28:48 pm »
thx you all for sharing your experiences.
Just ordered one Applent AT8612 in UK
http://www.tester.co.uk/applent-at8612-dc-electronic-load

 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #26 on: December 03, 2015, 10:41:39 am »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

« Last Edit: December 03, 2015, 10:52:05 am by AgiRigSig »
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #27 on: December 04, 2015, 02:01:51 am »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

could you upload the latest firmware please?
 

Offline AgiRigSig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #28 on: December 04, 2015, 10:34:41 am »
Hi thefamiliyman,

PM me your email and I'll send it to you :)

Have you made some test with the Software for the DC-Load?

 

Offline Danjensen89

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Re: Applent AT8612 DC load - a quick tear down
« Reply #29 on: January 13, 2016, 09:23:20 pm »
Hi Guys.
Very happy i found this thread. I have 2 of those and uses them in my shop.
I see you guys knows more about the units then i found in the manual.
I have 3 questions.
How do i upgrade the firmware? usb front?
Anyone wants to share the 2.9 version firmware? the hard reset battery test thats resetting the measured capacity is a major draw back for me.
Last question, some one also talked about software from applent site, i have searched that site down to ground, and dident fint that software, it would make my use of the units SO much better. Can anyone provide an link?

Regards, Dan.
 

Offline diyaudio

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Re: Applent AT8612 DC load - a quick tear down
« Reply #30 on: January 13, 2016, 09:44:51 pm »
VERY interesting, while the interface is different, the load portion itself is very much related to the Mayuno M9812 but with upgraded parts.

Maynuo:


Yours:
https://www.eevblog.com/forum/testgear/applent-at8612-dc-load-a-quick-tear-down/?action=dlattach;attach=159539;image

Yours has upgraded vertical sandstone resistors instead of the flat laying large wattage resistors. Yours has a higher quality R-core transformer. In general, the fit and finish look much better on yours than the Maynuo but there is VERY clearly a strong relationship between the designs. Everything is in the same general locations, most of the same parts are there, etc. It looks like one is a revision of the other and that is it.

EDIT: Your LCD-POO comment made me actually laugh out loud.

Someone needs to start reverse engineering these designs already, they all look similar and pretty straight forward
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #31 on: January 22, 2016, 01:00:26 am »
Well, you can add me to the AT8612 owners list... at least once it arrives.

I'll be needing to switch it to 120V operation, which I don't suspect will be too difficult based on a previous post mentioning the transformer has 2 120V primary windings that are connected in series in the 220V model.

I actually couldn't find a 120V version anywhere, and especially not on Aliexpress!
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #32 on: February 01, 2016, 01:43:37 am »
So my AT8612 arrived on Friday, direct from HK via DHL. It wasn't double boxed, and slightly damaged in shipping (the banana jack got pushed in and broke the plastic on the front panel a little). It did arrive with a US (110V) power plug, and the 110V/220V selector switch set to 110V on the back! So, was it actually ready to roll on 110V... probably not (but I never actually tried it). After reading a previous post in this thread that the 110 / 220 v switch wasn't connected, I did what Dave would do, and didn't turn it on, but took it apart!!





So, what do we have... yup, indeed the 110V / 220V selector switch IS NOT CONNECTED AT ALL:


Also, a bit of a design flaw with the ribbon cable of the display rubbing on the corner of the transformer mounting bracket... not good... hopefully the screen will still work...


Looking at the transformer, it indeed has 2 110V primary windings, and 2 secondary windings: a 13vac winding, and a +/- 13vac winding with center tap. A little common sense and looking at the secondary wires from the transformer leads to decoding the Chinese characters for Yellow Black and Green. A little googling to look up the Chinese symbol for Red and Blue, and you can easily figure out all the labeling on the transformer:


So originally on the primary, there's a plug that comes from the board and has blue and red going to the transformer, and yellow and black are tied together under a piece of heat shrink. Just out of curiosity, I plugging it in with 110V and measuring the open circuit voltage on the secondaries. You'll get 8vac on the green pair, and 16vac on the yellow pair, when we're expecting 13vac and 26vac respectively as per the label on the transformer. It's probably not going to work as is on 110vac input...



To reconfigure the transformer primaries for 110V operation, both 110V coils must be wired in parallel. I cut the red and blue leads going to the connector, and cut the yellow and black apart that were connected initially on the transformer. I connected red from the plug to red and yellow on the transformer, and blue from the plug to blue and black on the transformer to put the 2 110V coils in parallel. It's important that red and yellow be tied together, and blue and black be tied together so that the coils are actually in parallel. Now connecting it to 110V input and measuring the secondaries, I saw 16VAC on green, and 32VAC on yellow. Slightly higher than the transformer label, but to be expected as I'm measuring the windings open circuit with no load.




So, ready to go with 110V operation. Let's hope the display still works...


Yes, it does luckily! I put some tape over the damaged ribbon cable to prevent it from rubbing on the transformer mount in the future. I also fixed the contacts to the banana jacks and got that straightened out, but didn't take a picture.

In the end, it's quite easy to convert this unit from 220V input to 110V input, but don't trust what line cord it comes with, or the input voltage switch on the back!!
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #33 on: February 01, 2016, 11:56:42 am »
Hi ahakman,

sorry for your damage; I also received the unit via DHL, but mine was very well packed and arrived in good shape.

I'm quite happy with this device, but some details clearly call for unprofessionalism.
The power selection switch for all: if the unit is set for 110V and the switch is unoperative, someday there may be a problem... I would prefer to properly wire the selector switch, so that if it says 220V there's no risk to fry the unit by plugging it into a 200+ V socket (actually, I didn't do it, but anyway my unit is set to 220V, so there's no risk of damage).

By the way, I found that this electronic load works fine well beyond its nominal parameters.
Making some quick evaluation, it should be able to continuously bear up to 500W and 300V [it might also be able to work up to 40A, but the firmware (correctly) limits the input current to 30A/300V in every possibile configuration].

In fact, I could proficiently use it up to >800W during a few minutes, and finally managed to blow it with a 1500 W power spike (around 75V at 20A).
One of the power mosfets (IRPF460) went shorted, but the unit went back to life by simply cutting it out.
Anyway, to be sure I replaced all of the 8 mosfets along with their insulating pads (a couple of them were broken), and now everything works like new -
no burning mark anywhere

Some criticism:
- I found that removing the input plugs' locking nuts was more difficult than needed
- Also, the power resistors placement made it difficult to replace 2-3 of 8 mosfets
- The blinking blue light is somewhat annoying to me  :)
- I'd like to be able to finely calibrate the device, but the service menu is password locked and I wasn't able to get the password from Applent (i.e. from Vera). And the firmware is encrypted, too. Maybe anybody could help?  ;)
- The remote control software (thanks thefamilyman!) is definitely less than perfect... but way better than the incredibly bad software usually released with many Chinese products.

All in all, nothing to really complain about, and I find this electronic load very good for its price (no rake-off from the seller...)

    Lucio.
 

Offline ahakman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #34 on: February 01, 2016, 10:38:24 pm »
Yeah, you could wire the selector switch like this and actually have it be functional (actually I think looking at the picture I drew the diagram backwards - the 220V selection is on the left side of the switch looking at the contacts, so flip around the blue and red and the black wire tying the two switch contacts together). I'll probably never have this in a 220V place, so I'm not overly concerned and probably won't bother.

What do you mean, "removing the input plugs' locking nuts was more difficult than needed"? Are you talking about the nuts holding the banana jacks to the thick leads that go to the board? I actually found that mine were tight, but not _that_ tight. Pretty sure they're much tighter now when I put it back together. Yes, they're kindof a pain, but not too bad. Would be really easy with a 12mm open ended wrench, which I couldn't find quickly (the set that I had at hand had 11mm and 14mm :( ), so I used some large bent nosed needle nose pliers to do it.

Yeah, the blue light is a little annoying - doesn't bother me that much, but you could always cover it with tape, or find it's resistor on the front panel board and increase the value so the led isn't as bright.

I also read about and saw where you have to enter the password on the service menu. I'd like to re-calibrate mine as well - the voltage reading is off by about 10mV. The current is a little off (few mA) compared to the Fluke DMM, but it's not linear across the range I checked it over... probably not that significant unless you're trying to do really precise things...
« Last Edit: February 01, 2016, 10:45:46 pm by ahakman »
 

Offline Zbig

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Re: Applent AT8612 DC load - a quick tear down
« Reply #35 on: March 30, 2016, 09:39:12 am »
Does it have slew rate (ramp-up/down rate) control? After a quick glance at the manual, I'm under impression that it doesn't, while the Maynuo 9800 series, based on the "similar" analog backend, do. Am I correct?
 

Offline hipfan75

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Re: Applent AT8612 DC load - a quick tear down
« Reply #36 on: May 21, 2016, 12:46:10 am »
So, thanks to the work of the earlier posters in this thread, and the fact that I too would purchase a poo with a colour LCD attached, I am now the proud owner of an AT8612.

One thing I'd like to point out to other prospective buyers is that the unit I received did NOT have a 110/220V transformer. On my unit, the primary was 220V only (see pic).  I have contacted Applent/Anbai to see if I can purchase a 110/220V transformer as seen in the earlier pictures in this thread.  I'll let you know how that works out.  Failing that, I'll just run it through an external step-up transformer.

Right now, I'm running it through my variac which can step up 110V to 250V. Looking good so far.  My unit, received yesterday, came with firmware A2.9.
 

Offline hipfan75

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Re: Applent AT8612 DC load - a quick tear down
« Reply #37 on: May 29, 2016, 01:20:46 am »
I have contacted Applent/Anbai to see if I can purchase a 110/220V transformer as seen in the earlier pictures in this thread.  I'll let you know how that works out.  Failing that, I'll just run it through an external step-up transformer.

So, Vera at Applent quickly responded to my query with a quote of US$70 (shipped to Canada) for the transformer.  I decided to stick with an external transformer, but credit to Applent for their excellent customer service.
 

Offline ivanroberto

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Re: Applent AT8612 DC load - a quick tear down
« Reply #38 on: January 01, 2017, 08:23:42 pm »
Hi, 
I need to calibrate my unit.
Vera from Anbai, told me that pass word is 861200
The problem is that there is no procedure description about to do this, and some buttons and sentences are in Chinese....
So,  if someone can help me with this, I healy appreciate.

Thanks in advance
 

Offline zocra

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Re: Applent AT8612 DC load - a quick tear down
« Reply #39 on: February 14, 2017, 07:09:48 pm »
It would be very good to know the procedure of calibrating the device, it would be good that the new firmware translate part of the calibration device

If anyone has a calibration process it would be nice to share it with others, thanks

I have A8612A and I am satisfied with it

 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #40 on: March 17, 2017, 03:33:53 am »
Add me to the I-need-another-LCD-instrument club. Just got my AT8612 fresh from Aliexpress. So far so good :-)

And one more installment in the 110V vs. 220V saga  >:D

I got a fresh unit build in Jan 2017.

Surprise! It came with a US power cable, a beautiful 110V/220V switch _and_ a little sticker marked 110V.
My hopes were high that after all that time they had added a proper voltage switch  :scared:  :scared:  :scared:



Before plugging it in, I opened it up to figure out what the wiring looked like (and to check if there was anything else needing attention). And... the voltage switch is not wired, as seen in other posts...  |O  |O  |O  |O



So I went to look at the transformer since some got one with 2 primary windings (110V/220V capable) while others got a single primary winding (220V only). And  ;D  ;D  ;D I got the dual winding one.

And then, triple bingo, it was wired in parallel, for 110V, just the way ahakman had proposed!  :clap:  :clap:  :clap:

So I got an actual 110V (non selectable) unit straight out of the factory   :-+  :-+  :-+



« Last Edit: March 17, 2017, 03:40:05 am by LaurentR »
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #41 on: March 20, 2017, 10:01:46 pm »
FYI
Just received a new Firmware from Applent (  from : vera at applent dot com ), this is the Version A2.9
No revision history available.

Now the Batterytest also shows the AH readings after a hard off from a smartbattery....
 
The first test with the Software Rev.1 from Applent ( thx. to thefamilyman ) was disappointing,
better to call it unusable...all readings/values from the AT8612 seems to scaled incorrectly and some inputs from the PC are not possible..
I am in contact with Vera from Applent an will inform you here if get any news
Torsten

Hi Torsten,
could you post the A2.9 firmware? Strangely, my unit is brand new and came with A2.3 and Vera claimed that A2.3 is the latest firmware. Weird.
Also, does anybody have any sw more recent than the v1.0.0 which has a number of issues?

Laurent
 

Offline DK-1

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Re: Applent AT8612 DC load - a quick tear down
« Reply #42 on: May 22, 2017, 08:12:04 pm »
If someone interested i just take the 2.5 upgrade for the AT8612A!
All seem to work perfectly....to be honest this upgrade has fix the only bug i had in my unit!
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #43 on: May 22, 2017, 09:41:28 pm »
If someone interested i just take the 2.5 upgrade for the AT8612A!
All seem to work perfectly....to be honest this upgrade has fix the only bug i had in my unit!

Hi DK-1. Which bug does the update fix? Could you post the 2.5 upgrade?

Thanks in advance.
 

Offline DK-1

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Re: Applent AT8612 DC load - a quick tear down
« Reply #44 on: May 23, 2017, 05:10:04 pm »
When i test the LED (in led window obviously) some function disappear.......i don't know why....anyway now it is been fixed!
P.M. for you LaurentR
 

Offline schmitt trigger

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Re: Applent AT8612 DC load - a quick tear down
« Reply #45 on: May 23, 2017, 05:11:43 pm »

 so the AT8612 became even more tempting at US$360+shipping.



The unit is within the correct price range for me too.
Mind you where did you purchase it?

The usual sites I've looked, are all above US$400 for the unit plus US$70 to US$100 shipping.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #46 on: May 23, 2017, 05:51:29 pm »

 so the AT8612 became even more tempting at US$360+shipping.



The unit is within the correct price range for me too.
Mind you where did you purchase it?

The usual sites I've looked, are all above US$400 for the unit plus US$70 to US$100 shipping.

I bought it from this seller on AE:
https://www.aliexpress.com/item/AT8612-Programmable-DC-Electronic-Load-300W-150V-30A-3-5-TFT-LCD-RS232-Handler-Battery/32733874549.html
It was $368 + free shipping back in February. It has gone up a bit but still <$400 and free shipping.
 
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Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #47 on: June 16, 2017, 07:40:53 am »
Hi there,

Just got the unit (AT8612, 220V).
The last firmware is 2.9 as Vera from Applent sent me the file (can share it if anyone needs it). Unit came with 2.5 version of firmware.
Another question I have cleared with Vera is that minimum resistance selectable is 0.1 Ohm even thought documentation says "resolution is 0.01 Ohm). I suspect that using SCPI it could be possible to select 0.0x values, have to test it.

Anyone knows any free software that uses SCPI language to gather data from the device? Original software is somewhat creepy and has no export to csv/excel data options so you could compare different tests afterwards (except for battery test - have to test it - if it exports the data and not only final results). In the end it is possible to write some small app that will do it..
 

Offline Kleinstein

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Re: Applent AT8612 DC load - a quick tear down
« Reply #48 on: June 16, 2017, 04:58:13 pm »
With electronic loads, one should be careful with higher voltages: The power MOSFETs usually have a much higher blocking voltage, but there also usually is an SOA limit. So at higher voltage the permissible power will go down (models go like proportional to voltage or voltage squared). The actual SOA limit when a FET will fail can very, often higher than specified, but no way to be sure.

The minium resistance is set by the shunts and the MOSFETs. The resolution is determined by the DAC and precision of the OPs. So there is no problem having resolution might finer than the minimum resistance. The actual limit might be a little smaller than the specs, especially of everything is cold.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #49 on: June 17, 2017, 05:32:55 pm »
Hi there,

Just got the unit (AT8612, 220V).
The last firmware is 2.9 as Vera from Applent sent me the file (can share it if anyone needs it). Unit came with 2.5 version of firmware.
Another question I have cleared with Vera is that minimum resistance selectable is 0.1 Ohm even thought documentation says "resolution is 0.01 Ohm). I suspect that using SCPI it could be possible to select 0.0x values, have to test it.

Anyone knows any free software that uses SCPI language to gather data from the device? Original software is somewhat creepy and has no export to csv/excel data options so you could compare different tests afterwards (except for battery test - have to test it - if it exports the data and not only final results). In the end it is possible to write some small app that will do it..

Thanks to sstepane for providing the A2.9 fw.

I installed it successfully over A2.5, but now, I am getting a "Runtime error 9, subscript out of range" late into the connection process of the 1.0.0 software. Flashing back to A2.5 fixes the issue. Anybody either has this error or has been successfully running the 1.0.0 sw on A2.9 (or has a more up to date version of the sw)?
 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #50 on: June 19, 2017, 01:06:41 pm »
I installed it successfully over A2.5, but now, I am getting a "Runtime error 9, subscript out of range" late into the connection process of the 1.0.0 software. Flashing back to A2.5 fixes the issue. Anybody either has this error or has been successfully running the 1.0.0 sw on A2.9 (or has a more up to date version of the sw)?

I've seen this error as well, did not try on 2.5 version though. I think it is a good idea to email Vera about this. Hope they will fix it (it should take couple of minutes as far as I understand - just to change parsing function in software).
Here's Vera's email - vera@applent.com. Let me know if You're not going to write to her - I will then.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #51 on: June 19, 2017, 02:30:17 pm »
I installed it successfully over A2.5, but now, I am getting a "Runtime error 9, subscript out of range" late into the connection process of the 1.0.0 software. Flashing back to A2.5 fixes the issue. Anybody either has this error or has been successfully running the 1.0.0 sw on A2.9 (or has a more up to date version of the sw)?

I've seen this error as well, did not try on 2.5 version though. I think it is a good idea to email Vera about this. Hope they will fix it (it should take couple of minutes as far as I understand - just to change parsing function in software).
Here's Vera's email - vera@applent.com. Let me know if You're not going to write to her - I will then.

Thanks sstepane. Just shot her an email.
Screenshot attached for reference.

 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #52 on: June 20, 2017, 12:46:02 pm »
Hi,

Vera said to address this issue when engineer will come from a trip.
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #53 on: June 20, 2017, 04:08:03 pm »
Hi,

Vera said to address this issue when engineer will come from a trip.

Now we know how many people they have working on this  :)
 

Offline thefamilyman

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Re: Applent AT8612 DC load - a quick tear down
« Reply #54 on: June 21, 2017, 05:17:57 am »
Mine has died.
wouldn't go over 10A and now cant even do 1A load on any setting.
cant be bothered repairing it.
 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #55 on: June 21, 2017, 07:44:43 pm »
Hi,

Anyone got it to work via serial port? Can't get any answer from it. Might be software related or I'm doing something wrong. Tried HyperTerminal and Putty under Windows, no response from the device. Original software queries the device ok.
 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #56 on: June 21, 2017, 08:55:58 pm »
Found it - you need to lock the keypad for the device to react to scpi commands over serial.
 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #57 on: June 26, 2017, 12:27:42 pm »
Hello,

Another nuance - if you're going to use SCPI commands with this device - some commands need a bit more time to execute - for example mode change command needs some delay (I use 0.5 sec) to complete.
For the moment I'm experimenting in writing some Labview routine to test li-ion battery along with temperature sensing from another device.
 

Offline rsivan

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Re: Applent AT8612 DC load - a quick tear down
« Reply #58 on: November 11, 2017, 11:34:22 am »
Hello I try to upgrade from fw A1.9 to A3.1, but after stuck at boot logo then I discovered there is 2 version of fw 8612 and 8612A
so the only fw which starting now is A2.2 for non "A" version, now calibration is gone ,I tried to enter password in service menu but cannot make calibration,if press zero key unit stuck in loop quickly triggering relay inside, does someone have procedure for calibration or also newer fw for non A version? I try to write vera@applent.com still waiting for a answer.

thanks
« Last Edit: November 11, 2017, 11:36:33 am by rsivan »
 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #59 on: November 11, 2017, 05:41:28 pm »
...similar situation here. Found a quite strange behavior on a newly shipped AT8612 (A?) which would display all current readings in CC mode if the set current hasn't been reached (i.e. unregulated) some odd 200mA too high. So if no current was applied (terminals unconnected) it read something like 203mA if for example a set current of 1A was selected and the load turned on. If the set current was below these displayed 2xx mA, the reading would be truncated at the set current. Otherwise, the device performed as expected. I purposely use past tense since...

Well, couldn't leave my hands off the "TFT equipped p..." and since the calibration access password was supplied here, I tried my luck and...of course...ruined the calibration completely. Is there any native chinese speaker present on this forum who could help with translating the messages displayed during calibration if I take a series of step-by-step photos of the screen? It's sill questionable if this would really help since the messages appear to be rather short and apparently no numbers (like currents/voltages to preset) are provided. But it may be worth a try nevertheless.

If someone would agree to assist, I'll go ahead and take some photos...

Even if the recalibration would be successful, I'm not sure if there might be another (hardware) problem with my instrument that caused that current offset to be displayed. Currently I'm somewhat reluctant to send it back to China since shipping would cost an arm and a leg and I can't be too sure if I'll ever get the device returned. And once in a while I like a challenge like this, I take it like a kind of sports...

Cheers,
Thomas
 

Offline casinada

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Re: Applent AT8612 DC load - a quick tear down
« Reply #60 on: November 11, 2017, 06:11:16 pm »
Did you try Google translate?  :-//
 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #61 on: November 11, 2017, 08:12:52 pm »
Problem is: I can't even enter the chinese symbols or know how to find them in a list or so. And considering the quality of an "automatic" chinese -> english online translation, I doubt that the result will be too useful. I might be wrong though. Does anybody know of some kind of "ocr translator" for chinese language where one can input photos of the symbols?

Cheers,
Thomas
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #62 on: November 11, 2017, 09:17:02 pm »
Hi there,

I experienced a similar problem a few months ago.

Starting the load after a long time, I found both current and voltage readings quite wrong.
A few weeks later I found the system password on this forum and made a try, but without success.
I also managed to get a translation of some chinese sentences which popped out during this process, but the problem is, I can't figure out what's the logic behind the required calibration procedure.

In attachment a Word doc with the pictures of the chinese sentences above and their translations (from an Asian languages scholar). Hope this helps - but I doubt it...
 
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Offline rsivan

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Re: Applent AT8612 DC load - a quick tear down
« Reply #63 on: November 12, 2017, 08:13:44 pm »
Thanks Lucio, I done some try also google translator android app can translate from pics,just add chinese lang and take shot,but for me procedure which is working are:
Reset(select label and press enter)it make kind of "cal reset" and make just row pecise but not 100% like 1A=830nA 2A=1998,3A=3.1A,4A=4,2A and so on,just need to cal voltage.
zero key=system going in loop triggering a  relay  but if quickly press trigger or enter key some time (10-20) is going out and show 0v at standby

voltage cal is working, ask you 2 reference value one for low range=18v and one for high=150v  ,I used 20v for high and 10v for low with rigol power supply and make cal ok 100% precise about V

current cal will ask you 2 reference,it drain 5,2A then 1.1A when ask I presume you should input a real value readed from PS,but in both any value you write don't change any for me I think there is some bug in fw,

if any one can dump flash  would be great because serial number can be  changed form service menu and adapt to other instrument is easy.

I write to Vera they are investigate about issue,send me 2 fw but stuck at boot with both.

Update
After contacted Vera they send me a 2.4 firmware which is working ,now calibration is working as well,instrument is up again and very precise!
if someone have problem I suggest you to contact Vera with serial number they are very fast and will send right fw to update without problem.


« Last Edit: November 15, 2017, 08:21:23 am by rsivan »
 

Offline luciof

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Re: Applent AT8612 DC load - a quick tear down
« Reply #64 on: November 17, 2017, 10:25:19 am »
Hi rsivan,

I have the same problems in calibration: managed to get correct voltage readings, but current is always way off (and current readings are not even linearly related to actual values).

My current firmware is A2.8, which Vera sent me two years ago to correct some bugs. This version allows me to use the AT8612 up to 300 V instead of 150 V.
My newest FW file is AT8612.151119.B2.9, with a minor bug correction in serial programming, but limited to 150 V (so I removed it after a quick test).

If I understand correctly, your 2.4 firmware version allows you to fully calibrate the instrument; is it accurate in both current and voltage?

Also, this sounds a little strange to me, because 2.4 looks like an old FW version.
But, if it enables calibration I may install it, perform calibration and then install back the A2.8.
So, may you kindly post the 2.4 FW for a quick try?

Thanks,
    Lucio.



 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #65 on: December 27, 2017, 12:56:02 am »
Recently I found some time to have a closer look at the peculiar behavior of my AT8612A - I reported that before but didn't get into too much detail. Actually, I found the cause and I was quite amazed that this slipped through Applent's QC... But let's first have a look what was strange: The first photo shows the load, set to CC mode with a current of 1A dialed in and switched off and nothing connected to it. Everything's fine, the display readings are as one would expect.

Now, all I did was activating the load's input, still nothing is connected to it and nothing else has changed to the previous photo: Mysteriously, the load is reading a current of 212mA now. I did some basic reverse engineering of the passbank circuitry which consists of eight individual current sinks, all controlled by the same control voltage that is generated by the circuitry around the main shunt. This configuration makes sure that the power dissipation is spread evenly across all eight passbank transistors. See the photo of my ugly whiteboard drawing of one channel's simplified schematic.

Some probing around didn't show anything special initially -- except gate voltage at the mosfets at the second glance... It was around 9V with the load enabled on EVERY transistor. Moreover, before the gate resistor(s) I measured something like 10.8V which means that the gate-source protection clamps started to conduct. And that's the cause of the current being displayed when the load is switched on. As soon as the load is actually controlling the current, the gate-source voltage of the passbank transistors will be lowered to a value slightly above the individual transistors threshold voltage -- considerably below the 9V that the clamps become conductive at. That's why the load appeared to work normally when it was controlling an external current. As soon as the external current is lowered below the preset value, the gate voltage is increased and again the clamps become conductive, which results in a current reading offset by the 200 odd milliamps.

The zeners of the gate voltage clamps have apparently been 8.2V type while they probably should have been rated at 12V. Seems like somebody installed the wrong feeder on the p&p machine... Whatsoever, I replaced all 16 zeners with 12V types and the problem was gone.

Since I had to remove the main PCB for this job, I found some ugly details in an otherwise neat design -- probably the "Danger" sign had been placed there to indicate the tiny creepage distance around the mains switch area  ;) - especially to the switch's metal mounting bracket. The pitch of the nearby connectors is 2.54mm for comparison. I'm quite surprised of this since in the other areas where mains power is routed across the PCB, the creepage clearances are ample or even isolation slots are milled through the FR4. Apparently, this ugly detail didn't cause any trouble yet.

I had been in touch with Vera who's really very kind and helpful. I discussed the calibration issue and the benefit of being able to do the job myself and she was so kind to send me a short instruction sheet (see attached PDF - slightly edited by me). With the help of this, I've been able to get the CC mode accurate again. It seems the voltage slope calibration requires a "proper" lab supply with at least 250V output voltage which I haven't got. I experimented with an electrophoresis supply but this is way too picky and shuts the output down all the time. Calibration of the current slope actually requires a power supply that outputs more than 30A - I used a 12V 1kW server PSU for that job and it worked a treat. I'll add the information about how to calibrate the voltage mode and what kind of PSU will do once I succeed.

At least there's some hope for all those of us who messed up the calibration or just want to do the job themselves. I'm most impressed by the amount of cooperation at Applent and can only say "Thank you, Vera".

All the best,
Thomas
 
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Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #66 on: January 18, 2018, 02:24:27 am »
Very interesting TurboTom.

I just received device and then I test it, I noticed one strange thing:

If the source device have current limit (for example on 3,000A in CC mode lab PSU) and if I try to set current on AT8612 more than this limit (3,500A for ex.) then Ammeter of AT8612 shows the value more then real current on 170..190mA (3,178A). It's not depend of Voltage or Current limit values. For example it shows 2,175A for 2,000 A limit or 1,179A fot 1,000A limit. Of course I checked real current with Multimeter. And I checked it with two Lab PSU (Agilent, GWInstek).

Can somebody reproduce this issue?

Also very strange action on low Ohm 0.1...2.0 in CR mode, not tested carefully yet.

Firmware REV A2.5.

Wrote Vera
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #67 on: January 18, 2018, 03:43:59 pm »
Mysteriously, the load is reading a current of 212mA now.

Seems like I has the same issue.

But all gone just after reflash to A3.2 (attached)
« Last Edit: January 18, 2018, 03:46:22 pm by Safar »
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #68 on: January 18, 2018, 04:00:50 pm »
But ghost current still here under the load  :-BROKE

Think same problem like TurboTom's device. Control current drain via protection circuit.

« Last Edit: January 18, 2018, 05:31:25 pm by Safar »
 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #69 on: January 18, 2018, 04:28:28 pm »
This is exactly the same behavior that I noticed on my AT8612A - I guess yours is suffering from the wrong zeners as well.

Open the casing, and just check the voltage between gate and source of an arbitrarily selected passbank transistor while the instrument is not connected and the input enabled. If you read round about 9V, the zener problem is present, if it's more like 11V, the passbank clamps are likely okay.

Good luck and all the best,
Thomas
 
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Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #70 on: January 18, 2018, 05:28:43 pm »
Yes, I did.

But I have another voltage, even more less.

In normal current regulation on 3A (17.5V source) voltage is 3,76V (#1 on pic). In short (CC 3.2A on source) voltage is 7,06V (#2).
It seems like 6,2V zeners installed in my device.

Exactly the same is happens if you push "on" without any source connected.

And I measure voltage drop on gate resistor: almost no current (#3) as expected in normal mode and about 2.74V (#4) on shorting. It correspond ~6mA for 470 Ohm gate resistor. All 8 resistor have almost the same voltage drop. So it about ~48mA total drain. OpAmp heated till 50 C degrees on this mode.

But why ghost current drain is 170mA? Anyway it need to fix.

Many Thanks for very helpful find! And where are zeners for outside MOSFETs? Under the heatsink?

And about A3.2 - it is very strange but it seems like just program cut small current for displaying when all gates opened (source not connected or source limit current). Not right solution. Do not recommend for install.

I will write to Vera and ask for another FW.
« Last Edit: January 18, 2018, 06:19:35 pm by Safar »
 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #71 on: January 18, 2018, 06:29:22 pm »
The indicated "ghost" current is higher than the actual current flowing through the gate-source voltage clamps since this current isn't flowing only through the (main) shunt resistor but also through the ground plane of the sense amplifier(s) where no load current ever should flow. This results in too high a reading.

Replace all 16 zeners with 12V versions and you should be okay. You'll have to remove the PCB from the casing, though, since some zeners are assembled on the solder side. Moreover, to access some of the zeners on the component side, you've got to temporarily remove the source resistors (the white power "bricks") of the passbank transistors. Otherwise, the job is straight-forward...

Cheers,
Thomas
 
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Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #72 on: January 19, 2018, 12:52:54 pm »
I wrote yesterday all measurements to Vera and ask engineer for information about zener nominal.

And the answer is 6.2V. Not funny.

Ok, I wrote now all explanations of ghost current and ask to provide this to engineer deps.

Let's see...
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #73 on: January 19, 2018, 12:55:10 pm »


The indicated "ghost" current is higher than the actual current flowing through the gate-source voltage clamps since this current isn't flowing only through the (main) shunt resistor but also through the ground plane of the sense amplifier(s) where no load current ever should flow. This results in too high a reading.

Replace all 16 zeners with 12V versions and you should be okay. You'll have to remove the PCB from the casing, though, since some zeners are assembled on the solder side. Moreover, to access some of the zeners on the component side, you've got to temporarily remove the source resistors (the white power "bricks") of the passbank transistors. Otherwise, the job is straight-forward...

Cheers,
Thomas

Thanks a lot for this helpful info
 

Offline audun

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Re: Applent AT8612 DC load - a quick tear down
« Reply #74 on: January 23, 2018, 11:34:59 am »
Hi!

Trying to decide if I should buy this load...

Would 1N5349B zeners be a good choice, if needed?

Anyone successfully connected the load to a computer via the front panel USB, instead of using the RS232 on the back?

Best regards Audun
« Last Edit: January 23, 2018, 11:42:09 am by audun »
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #75 on: January 23, 2018, 12:53:48 pm »
I suppose you cannot fit this in place of protection circuit as here SOT-80 package zener, I ordered BZV55-B12 for changing.

Actually it can be possible of course, but.... :)

About USB I think that it is USB-host only port and it can works with USB storage devices only.

RS232 it is right solution here as it can be isolate by more simple way then USB, that is important for this kind of equipment.

By my opinion, this is interesting device for this money, but I do not tried more serious brands, so it just my vote.
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #76 on: February 05, 2018, 11:31:00 pm »
FW v3.1.

Last FW without current cut issue.
 

Offline KaasimAli1

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Re: Applent AT8612 DC load - a quick tear down
« Reply #77 on: March 14, 2018, 11:09:45 am »
Hello,

Another nuance - if you're going to use SCPI commands with this device - some commands need a bit more time to execute - for example mode change command needs some delay (I use 0.5 sec) to complete.
For the moment I'm experimenting in writing some Labview routine to test li-ion battery along with temperature sensing from another device.

Hello,

i am too trying to control my device from using LabVIEW, i have been able to turn onthe device and send a desired current to it. but after receiving the current the device turns off and back on when the next current needs to be read. i have tried lots of things to combat this but there is a sequence function in the user manual that i am trying but cant get it to work. i was wondering if you could help on this or even comment on how useful you are finding labview at communicating with this device? 

thanks
Kas
 

Offline sstepane

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Re: Applent AT8612 DC load - a quick tear down
« Reply #78 on: March 14, 2018, 11:53:02 am »
Hello,

Another nuance - if you're going to use SCPI commands with this device - some commands need a bit more time to execute - for example mode change command needs some delay (I use 0.5 sec) to complete.
For the moment I'm experimenting in writing some Labview routine to test li-ion battery along with temperature sensing from another device.

Hello,

i am too trying to control my device from using LabVIEW, i have been able to turn onthe device and send a desired current to it. but after receiving the current the device turns off and back on when the next current needs to be read. i have tried lots of things to combat this but there is a sequence function in the user manual that i am trying but cant get it to work. i was wondering if you could help on this or even comment on how useful you are finding labview at communicating with this device? 

thanks
Kas

Hi,

I have not tried the sequence function, but from what I understand - the idea is that You once setup the device, then turn it on (load on), then read data from it (fetch). If You're trying to set it while it is turned on (load is on) - it is likely it will reset.
If your entire routine does work without remote control - it should work via remote control as well.
 

Offline s8472

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Re: Applent AT8612 DC load - a quick tear down
« Reply #79 on: October 15, 2018, 06:31:55 am »
FW v3.6
 

Offline LaurentR

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Re: Applent AT8612 DC load - a quick tear down
« Reply #80 on: October 15, 2018, 03:34:05 pm »
FW v3.6

Any idea what's in it and the reason why it was released?

Laurent
 

Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #81 on: October 16, 2018, 03:33:10 pm »
Could someone possibly publish how the firmware update procedure is? I tried loading it on a thumb drive but I didn't find any menu item to flash it. Didn't try with the Applent PC software though, as yet I didn't use it. Is the firmware supposed to be flash with this application or is there another trick that's not obvious (I'm on F/W 3.1 currently). Thanks for the hint!

Cheers,
Thomas
 

Offline Safar

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Re: Applent AT8612 DC load - a quick tear down
« Reply #82 on: October 16, 2018, 04:48:52 pm »
I found it in message from Vera:

1. Plug the U disk into your PC and copy the attached file “xxxxxxxxx.atos” to the root catalog of the U flash disk. After finish copying, unplug the U flash disk from PC and then insert U flash disk into the U-disk interface of AT8612.

2. Press the numeric key "5" and ”8” at the same time, please don't release the number key, then start AT8612, then the instrument screen will appear Program burn page.

3. Press numeric key to select according to instruction on the screen, then press <enter>, and then wait for the process of update.
 
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Offline TurboTom

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Re: Applent AT8612 DC load - a quick tear down
« Reply #83 on: October 17, 2018, 02:55:54 pm »
I believe the more recent AT8612's are "A" versions. If I ckeck the system ID page, it tells "AT8612A". I wouldn't bother too much about that, it's probably more like an internal "revision identifier" for applent than a real difference in specs.

By the way, did anyone succeed in a full calibration of the load? I always seem to fail at the voltage slope calibration. Maybe my problem is that I haven't got a lab power supply with sufficiently high current capabilities at 250V (only got 1A available). Current slope calibration requires a pretty powerful source as well, but fortunately no high voltage is required here. I use a 12V / 1kW server power brick for this. Without proper slope calibration, the instrument will display the correct values for voltage / current (provided these calibration steps were accomplished successfully) but it will fail to load the correct currents / voltages. I hope someone has succeeded with the voltage slope calibration and can specify what kind of power supply is required to get this done.

The new firmware (Rev. 3.6) has got a much more elaborate calibration routine with considerably more reference points. If that's a real advantage in terms of accuracy is another question. Current calibration takes a long time after entering the measured value (~1minute) during which the instrument becomes unresposive and seems to be "hung up".
 

Offline Logic001

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Re: Applent AT8612 DC load - a quick tear down
« Reply #84 on: April 25, 2019, 07:02:35 pm »
Hi,

Can someone please post any firmware version newer than V2.2 for the AT8612 (not the A version).
I tried to upgrade my unit that was with version 3.0 to version 3.6A and the unit didn’t boot up. I tried few others A versions and they are not working.
I also tried to contact Applent without any luck.

Thanks.



 

Offline mnsergey

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Re: Applent AT8612 DC load - a quick tear down
« Reply #85 on: June 12, 2019, 09:49:29 am »
I welcome dear community.
I also bought AT8612 and waiting for his arrival. While studying the issue of software for this device. On the official website www.anbai.cn there is software only on Chinese. I downloaded it, installed it, but ignorance of Chinese does not allow me to fully evaluate this software. Anybody have the software in English for AT861X ? You can even give a link to the demo version to make an assessment.
Thanks in advance who responds.
 

Offline mnsergey

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Re: Applent AT8612 DC load - a quick tear down
« Reply #86 on: June 13, 2019, 09:08:54 am »
Hi,

Can someone please post any firmware version newer than V2.2 for the AT8612 (not the A version).
I tried to upgrade my unit that was with version 3.0 to version 3.6A and the unit didn’t boot up. I tried few others A versions and they are not working.
I also tried to contact Applent without any luck.

Thanks.

Have you resolved this question in firmware? I recently contacted VERA on another matter. Always respond promptly. (vera@applent.com) If you want, I'll contact them again. Just describe the specific problem, it will simplify the solution.
 

Offline Logic001

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Re: Applent AT8612 DC load - a quick tear down
« Reply #87 on: June 21, 2019, 12:27:37 am »
Thanks for trying to help.

The issue is that I tried to upgrade my unit AT8612 with version 3.6A without knowing that there are two different units the A version and non A version.
I looks like that the firmware are not compatible.
I would like to have the last firmware for the none A version.
The version I am running know is 2.4 the only one I could found that is actually older than the original version I had 3.0.
Also another issue I have is after playing with the firmware upgrades the voltage measurements are really off by a lot. I tried to calibrate base on the information I found here without any success.
I am not sure now if it is only firmware version, something wrong with the unit or wrong calibration process.
In the end I have nonfunctional unit.
I will appreciate any help.
 


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